Detonating fuse for bombs and the like



Dec. 24, 1968 G- J. o. BODINAUX DETONATING FUSE FOR BOMBS AND THE LIKE 2 Sheets-Sheet 1 Filed April 28, 1967 INVENTOR. $.10, Boclinaux ATTO I'LNEihSS Dec. 24, 1968 Filed April 28. 1967 G. J. o. BODlNAUX 3,417,701

DETONATING FUSE FOR. BOMBS AND THE LIKE 2 Sheets-Sheet 2 VENTOR.

IN O. Bot/477C101 BY I GLZJwJ QI- 51W ATTORNEHS United States Patent 3,417,701 DETONATING FUSE FOR BOMBS AND THE LIKE Gaston Jean 0. Bodinaux, Seny-eu-Condroz, Belgium, assignor to Les Forges de Zeebrugge S.A., Herstal-lez- Liege, Belgium, a company Filed Apr. 28, 1967, Ser. No. 634,735 Claims priority, application Belgium, Oct. 28, 1966, 688,993 Claims. (Cl. 102-75) ABSTRACT OF THE DISCLOSURE A d-etonating fuse of a bomb is provided with an additional safety device to cause the explosion at a predetermined time after impact, the device having an additional locking element for the movable detonator carrying member, whereby the locking element is released after impact by a portion of the pyrotechnic chain conditioned for that purpose.

This invention relates to a detonating fuse for bombs and the like, said fuse being conditioned to allow a bombardment at low altitude, while providing a maximum safety to the releasing plane.

More particularly, this invention relates to a detonating fuse for bombs and the like of the type comprising an arming mechanical device provided to release, after a given time and by the withdrawal of a locking element, a moving detonator carrying member, characterized in that the said detonator carrying member is controlled by a second locking element, the latter being made inactive after impact by the combustion of a portion of the pyrotechnic chain conditioned for that purpose.

The object of the present invention is to provide means for maintaining the said pyrotechnic chain not aligned for a given time after impact, particularly to provide a maXimum safety to the releasing plane, principally when bombarding at low altitude. For that purpose, the present invention provides additional means for locking the said detonator carrying drum, said additional means being made inactive after impact by the combustion of a portion of the pyrotechnic chain conditioned therefor. Due to this arrangement, any risk of explosion of the bomb at the impact is systematically avoided, said explosion occurring with a predetermined delay and independently from the proper percussion.

The characteristics and the advantages of this invention will be more apparent by the following description of an embodiment thereof given by way of illustration and without any limitation, reference being made to the enclosed drawings in which:

FIGURE 1 is a longitudinal section of a fuse according to the invention, the plane of said section being indicated on line II of FIGURE 4 and FIGURES 2 to 7 are sections according to the lines indicated on FIGURE 1 respectively as IIII, III-III, IV-IV, V-V, VI-VI and VIIVII.

The fuse represented in the enclosed drawings comprises a fuse body 1 on which is mounted a moving head 2 containing namely a reducing gear 3 of a known type and which is not therefore further represented. When the bomb provided with the fuse has been released, this reducing gear 3 actuates the angular movement of a hammer rod 4 moving axially within body 1 and coaxial therewith. This rod 4 is provided with a cylindrical mass 5 and enters, at the hammer side 6, the axial bore 7 of a hammer guide 8. The rod 4 is provided with a groove 9 into which penetrates a projection 10 of the bore of the hammer guide 8 (FIGURE 6) in such manner that the angular movement of rod 4 causes a similar angular movement of 3,417,701 Patented Dec. 24, 1968 ice the hammer guide 8. The annular base 11 of the hammer guide 8 opposes normally any axial movement of a rod 12 returned to said hammer guide 8 by a spring, the free end of said rod 12 being provided with a locking piston 13. In the position represented in FIGURE 1, said piston is arranged to oppose any rotating movement of the detonator carrier 14 about its axis 15 under the action of spring 16 (FIGURE 4). A cut-out 17 is provided in the annular base 11 of the hammer guide 8 in such manner that, when the latter is rotating under the effect of reducing gear 3, this cut-out 17 comes, after a given time, in front of said rod 12, the latter being then allowed to escape freely under the action of its spring 13. With the view of avoiding any accidental operation of the fuse, e.g., by handling, the annular base 11 of hammer guide 8 is provided with an approximately semi-circular groove 18 into which is engaged the end of a shear pin 19 carried by the corresponding end of said rod 12.

To avoid any axial rotation of piston 13, the latter is provided with a longitudinal groove 20 into which is engaged one end of a guide pin 21 inserted in a housing 22 of the fuse body. In addition, on a portion of its periphery, piston 13 is provided with a recess 23 into which, when the said piston is moved to its inactive position, is engaged the end of a lock 24 actuated by a spring 25 (FIGURE 5 In this way, piston 13 is prevented to return into the locking position at the impact.

According to this invention, there is provided an additional means for locking the detonator carrier 14, said means consisting substantially of an axially moving rod 26 one end of which is engaged, in normal locking position, into a semi-cylindrical recess 27, provided therefor at the periphery of the detonator carrier 14. The said rod 26 extends through a guiding bore 28 and then into a cylindrical chamber 29, said chamber being provided in the fuse body. Within chamber 29, the rod 26 carries a piston 30 engaging with an easy fit the wall of said chamber 29, said rod 26 being ended by a conical head 31. The rod 26 being in a locking position, its conical head 31 bears upon a fan washer 32 leaning with its outer edge on the rim of a curved opening 33 provided in the bottom of said chamber 29.

The said chamber '29 communicates upstream of piston 39 relative to conical head 31 with an axial bore 34 provided in the fuse body via two blind bores at right angles 35 and 36 respectively (FIGURE 3). Said blind bores are closed the one by a pin 37 and the other, by a screw 38.

Into the axial bore 34 is introduced a delay charge 39, the said axial bore being closed at the hammer side 6 by a primer 40 and, at the side of the detonator carrier 14, by a relay 41. The primer 49, the delay charge 39, the relay 41 and the detonator 42 are forming the pyrotechnic chain of the fuse.

The above described fuse operates as follows: the arming is effected as usual by rotating the reducing gear 3, the angular movement of which during a given time brings the cut-out 17 of base 11 in front of rod 12 of the locking piston 13 after having sheared pin 19. The rod 12 is then pushed back by the spring to such a distance that the piston 13 releases the detonator carrier 14, said piston 13 being kept in its inactive position by means of lock 24 which, under the action of its spring 25, penetrates the recess 23 provided on the said piston 13. At that time, the detonator carrier 14 is always kept in its initial position by the end of rod 26.

At the time of the impact, the inertia of mass 5 brings violently the hammer 6 against primer 40 which fires the delay charge 39. The latter, preferably conditioned to burn in parallel layers has a predetermined combustion time. After a certain combustion time, the passageway 36 is freed and the combustion gases are penetrating, via passages 36 and 35, into chamber 29 in which they retract piston 30, thereby causing rod 26 to unlock the detonator carrier 14. During the displacement of said rod 26, the conical head 31 thereof penetrates into opening 33 by slightly forcing the fan washer 32, the latter being then closed back to avoid any return of said rod 26. During the combustion of the remaining delay charge 39, the detonator carrier 14 is angularly displaced by its spring 16 about its pivot 15 in such manner as to bring detonator 42 into alignment with the pyrotechnic chain of the fuse. At the end of the combustion of the delay charge 39, the latter fires relay 41 which, in turn, fires detonator 42.

Thus, the above described device allows to obtain always after impact a delay equal to the predetermined combustion time of the delay charge 39 provided, of course, that the arming mechanism has operated. In addition, any risk of accidental firing of the bomb by the percussion of detonator 42 at the impact is eliminated since the latter is kept away from the pyrotechnic chain at the impact and well after the latter. This feature is particularly important when bombarding at low altitude, for which case it is, of course, essential that the releasing plane be not damaged by the blow of the explosion of the bomb just released.

It is apparent that numerous modifications may be brought as well to the shape of each constituting element of the foregoing device as to their respective positions without departing from the scope of the invention as defined in the following claims.

What I claim is:

1. A detonating fuse for bombs and the like, comprising a mechanical arming device having a locking member, a detonator, a movable member carrying said detonator and released after a given time by the withdrawal of said locking member, a rod constituting a second locking member and controlling said detonator carrying member, a fuse body having an axial bore and a second bore parallel to said axial bore, a delay charge located in said axial bore, said delay charge and said detonator constituting a pyrotechnic chain, said rod extending into said second bore, and a piston connected with said rod, the space between an end of said second bore and a face of said piston communicating with said axial bore, said rod being rendered inactive as a locking member after impact by combustion of a portion of said pyrotechnic chain.

2. A detonating fuse according to claim 1, wherein said communication opens into the said axial bore at a given distance from the end through which the said delay charge is fired, the value of said distance being calculated in accordance with the total combustion time of the said delay charge and the time necessary for displacing the said detonator carrying member from its inactive position into active position in which the detonator is in alignment with the said delay charge.

3. A time fuse for a bomb and the like, comprising a casing, movable percussion means, a body member having an axial bore and a second bore parallel to said axial bore, a movable carrier, a detonator mounted in said carrier, said movable percussion means, said body member and said movable carrier being located one next to the other in said casing, a delay charge located in said axial bore and having an end normally located in front of said percussion means, the other end of said delay charge being normally located out of alignment with said detonator, thereby interrupting a pyrotechnic chain formed by said delay charge and said detonator, a locking element mounted in said second bore and normally locking said movable carrier, and a piston connected with said locking element, said body member having a passage extending between said axial bore and said second bore and terminating at one end at a distance from an end of the axial bore and terminating at the other end between said piston and the end of said second bore which is adjacent to said movable carrier, whereby said percussion means upon impact of the bomb, fires said delay charge, whereupon the combustion gases of the delay charge after a predetermined combustion period reach said piston through said passage and displace said locking element which frees said movable carrier, whereupon said carrier moves into an armed position in which said pyrotechnic chain is established, whereby said detonator is fired after complete combustion of said delay charge.

4. A time fuse in accordance with claim 3, wherein said body member has a third bore, said time fuse further comprising another locking element mounted in said third bore and normally engaging said movable carrier, and means displacing said other locking element during the flight of the bomb.

5. A time fuse in accordance with claim 3, wherein said locking element consists of a rod having a conical head located away from said movable carrier, said time fuse further comprising an elastic fan washer located in front of said conical head, said rod when displaced penetrating into said fan washer which then closes to prevent the return of the rod.

References Cited UNITED STATES PATENTS 1,898,073 2/1933 Woodberry 10282 2,005,053 6/1935 Schlafer 10272 2,838,999 6/1958 Corsi 10272 2,984,184 5/1961 Cetre 10284 X 3,119,336 1/1964 Hjelm 10272 BENJAMIN A. BORCHELT, Primary Examiner.

G. H. GLANZMAN, Assistant Examiner.

US. Cl. X.R. 10276, 82 

